A study links amylase gene to obesity

Published online 2 April 2014

Aisha El-Awady

An international team of researchers have linked copy-number variations (CNVs), a form of structural variations in chromosomes that result in the reduction or duplication of one or more regions of the chromosome, to obesity.

The researchers, led by Mario Falchi from Imperial College London (ICL) and Philippe Froguel from ICL and Qatar Biomedical Research Institute, and including researchers from Qatar and Saudi Arabia, studied the influence of a CNV affecting the number of copies of the salivary amylase gene AMY1 and obesity, publishing their findings in Nature Genetics.

Salivary amylase is an enzyme produced by the salivary glands that aids in the breakdown of starch. Using an integrative genomic approach, the researchers identified CNVs in the DNA that affect the expression of genes located within their boundaries and investigated the influence of these genes on body weight.

People with decreased numbers of copies of AMY1 (<4) were found to have a higher body mass index (BMI), and were up to eight times more likely to develop obesity than people with a higher number of copies of the AMY1 gene (>9). This finding was replicated in more than 5,000 people from France, the UK and Singapore.

Falchi says this study "may potentially lead to future personalized plans for prevention of obesity, and potential treatment based on the manipulation of levels of digestive enzymes."